
#include <QPainter>

#include "edge.h"
#include "node.h"

#include <math.h>

static const double Pi = 3.14159265358979323846264338327950288419717;
static double TwoPi = 2.0 * Pi;

Edge::Edge(Node *sourceNode, Node *destNode)
    : arrowSize(10)
{
    setAcceptedMouseButtons(0);
    source = sourceNode;
    dest = destNode;
    source->addEdge(this);
    dest->addEdge(this);
    adjust();
	colorEdge=0;
}

Edge::~Edge()
{
}

Node *Edge::sourceNode() const
{
    return source;
}

void Edge::setSourceNode(Node *node)
{
    source = node;
    adjust();
}

Node *Edge::destNode() const
{
    return dest;
}

void Edge::setDestNode(Node *node)
{
    dest = node;
    adjust();
}

void Edge::adjust()
{
    if (!source || !dest)
        return;

    QLineF line(mapFromItem(source, 0, 0), mapFromItem(dest, 0, 0));
    qreal length = line.length();

    prepareGeometryChange();

    if (length > qreal(20.)) {
        QPointF edgeOffset((line.dx() * 10) / length, (line.dy() * 10) / length);
        sourcePoint = line.p1() + edgeOffset;
        destPoint = line.p2() - edgeOffset;
    } else {
        sourcePoint = destPoint = line.p1();
    }
}

QRectF Edge::boundingRect() const
{
    if (!source || !dest)
        return QRectF();

    qreal penWidth = 1;
    qreal extra = (penWidth + arrowSize) / 2.0;

    return QRectF(sourcePoint, QSizeF(destPoint.x() - sourcePoint.x(),destPoint.y() - sourcePoint.y())).normalized()
																				 .adjusted(-extra, -extra, extra, extra);
}

void Edge::paint(QPainter *painter, const QStyleOptionGraphicsItem *, QWidget *)
{
    QPointF t1;
	QPointF t2;
	if (!source || !dest)
        return;
	QLineF line(sourcePoint, destPoint);
	QLineF line1;
	QLineF line2;
	float r;
	float k, b, x, y;
	//edgeText = "0";
	r = edgeText.length()*4 + 3; 
	if(qAbs(destPoint.x() - sourcePoint.x()) > 8*edgeText.length() + 20 || qAbs(destPoint.y() - sourcePoint.y()) > 20)
	{
		t1.setX((sourcePoint.x() + destPoint.x())/2);
		t1.setY((sourcePoint.y() + destPoint.y())/2);
		line1 = QLineF(sourcePoint, t1);
		line1.setLength(line1.length() - r);
		line2 = line1;
		line2.translate(line1.dx() + 2*((sourcePoint.x() + destPoint.x())/2 - line1.x2()), 
			line1.dy() + 2*((sourcePoint.y() + destPoint.y())/2 - line1.y2()));
		if (qFuzzyCompare(line.length(), qreal(0.)))
	     return;
		//Draw edje text
		painter->drawText(sourcePoint.x() + 0.5*(destPoint.x() - sourcePoint.x()) - 5*edgeText.length()/2,
					  sourcePoint.y() + 0.5*(destPoint.y() - sourcePoint.y()) + 5,edgeText);
		 // Draw the line itself
		if(colorEdge == 1)
			painter->setPen(QPen(Qt::red, 1, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
		else
			painter->setPen(QPen(Qt::black, 1, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
		painter->drawLine(line1);
		painter->drawLine(line2);
	}
	else
		painter->drawLine(line);
    // Draw the arrows
    double angle = ::acos(line.dx() / line.length());
    if (line.dy() >= 0)
        angle = TwoPi - angle;

    QPointF sourceArrowP1 = sourcePoint + QPointF(sin(angle + Pi / 3) * arrowSize,
                                                  cos(angle + Pi / 3) * arrowSize);
    QPointF sourceArrowP2 = sourcePoint + QPointF(sin(angle + Pi - Pi / 3) * arrowSize,
                                                  cos(angle + Pi - Pi / 3) * arrowSize);   
    QPointF destArrowP1 = destPoint + QPointF(sin(angle - Pi / 3) * arrowSize,
                                              cos(angle - Pi / 3) * arrowSize);
    QPointF destArrowP2 = destPoint + QPointF(sin(angle - Pi + Pi / 3) * arrowSize,
                                              cos(angle - Pi + Pi / 3) * arrowSize);

    painter->setBrush(Qt::black);
   // painter->drawPolygon(QPolygonF() << line.p1() << sourceArrowP1 << sourceArrowP2);
    painter->drawPolygon(QPolygonF() << line.p2() << destArrowP1 << destArrowP2);        
}
